Lake 713,
I like Homer boy have had both K frame magnums from model 13 to 66. They are perhaps the finest shooting revolver ever made from S&W. But the revolver that I have owned the longest is a well use Ruger Police Service Six 4 inch. It has seen many rounds mostly 357 magnum from 125 to 158 grain. Its still as tight with no issues from the beginning in 1985. You have too decide. If you intend to shoot 357 magnums by a Ruger. It not, then a K frame magnum would be a excellent choice. By the way, Ruger did make Speed Sixes with 3 inch barrels. They are not common but are still more affordable than a S&W.
Good luck,
Howard